A short review of the distribution of short-beaked common dolphins (Delphinus delphis) in the central and eastern North Atlantic with an abundance estimate for part of this area

  • Ana Cañadas Alnitak. Nalón 16, E 28240 Hoyo de Manzanares, Madrid
  • Greg P Donovan International Whaling Commission, The Red House, Station Road, Impington, Cambridge CB4 9NP
  • Geneviève Desportes GDnatur, Stejlestræde 9, DK 5300 Kerteminde, Denmark and Faroese Museum of Natural History, Fútalág 40, FO-100 Tórshavn, Faroe Islands
  • David L Borchers RUWPA, The Observatory, University of St Andrews, Fife, KY16 9LZ
Keywords: surveys, short-beaked common dolphins, Delphinus delphis, distribution

Abstract

This paper uses data from 3 programmes: (1) the North Atlantic Sightings Surveys (NASS) surveys undertaken throughout much of the central and eastern North Atlantic north of about 40° N in 1987, 1989, 1995 and 2001; (2) the MICA-93 programme; and (3) the north eastern Atlantic segment of the Small Cetacean Abundance in the North Sea (SCANS) survey in 1994. The data from all surveys were used to examine the distribution of common dolphins in the NE Atlantic. No sightings were made north of 57° N. An initial attempt to examine distribution against 4 potential non biological explanatory variables was made. A simple interpretation of the preliminary analyses presented here is that the primary areas for groups of common dolphins were in waters over 15° C and depths of 400-1,000 m (there does appear a link with shelf features), between around 49°-55° N especially between 20°-30°W. An illustrative example of spatial modelling is presented. Only for 1 year (and part of the total survey area) were there sufficient data to attempt to estimate abundance: 1995. The estimated abundance in the W Block of the NASS-95 Faroese survey was 273,159 (cv=0.26; 95% CI=153,392-435,104) short-beaked common dolphins. This estimate is corrected for animals missed on the trackline (g(0)) and for responsive movement.
Published
2009-09-01
How to Cite
CañadasA., DonovanG. P., DesportesG., & BorchersD. L. (2009). A short review of the distribution of short-beaked common dolphins (<i>Delphinus delphis</i&gt;) in the central and eastern North Atlantic with an abundance estimate for part of this area. NAMMCO Scientific Publications, 7, 201-220. https://doi.org/10.7557/3.2714